Oil mop method and apparatus for producing an oil well

ABSTRACT

The present disclosure is directed to raising oil from shallow oil wells in which the oil generally of a high viscosity lays on top of a subterranean pool of oil and water. An endless mop of petrophilic hydrophobic fibers or thin gauge narrow strips is run down the well casing and placed in contact with the oil which it sorbs and which is entrained by the strips and raised to the surface where it is wrung from the mop and collected while the mop is returned to the oil pool to become ladened again with oil which will be brought to the surface.

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OIL MOP METHOD AND APPARATUS FOR PRODUCING AN OIL WELL An object of thepresent invention is to-produce crude oil from relatively shallow, i.e.,200 feet to 2,500 feet deep, oil wells. I-Ieretofore, it has not beeneconomically feasible to produce crude oil from certain of these shallowwells because of the very high viscosity, i.e., 50,000 S.U.S., of theoil, the very low oil-water ratio where it is not economically feasibleto pump the large quantities of water necessary to produce a suitablequantity of crude oil and in combination the disposition of thepollutants, i.e., salt water brought up with the crude; a combination oftwo or more of these factors.

Another object of the invention is to provide a method of selectivesorption of the oil, consequently mitigating the quality of waterbrought to the surface of the earth in a mop where whence the mop iscleansed of the oil and paid back down the hole to pick up additionaloil.

The quantity and quality, i.e., water-free of the crude oilproduced bythis new invention will vary with several factors including, but notlimitedto, the size and speed of the mop; viscosity of the oil;efficiency of cleansing the mop; the oil-water ratio; the porosity ofthe surrounding crude oil-producing geological structure whichdetermines the rate at which the oil will flow to the mop; themechanical arrangement of the downhold easements.

The mop consists of petrophilic hydrophobic'fibers, such aspolypropylene or similar material approximately 3-mils thick by 16inches wide, by 4 to 16 inches long, interwoven into a l/l6-inchdiameter to l-inch diameter wire rope or'rope, weighing approximately0.0. pounds to L pounds per linear foot and approximately 400 feet to5,000 feet long, and is of the type shown and described in my .copendingU. S. Pat. application Ser. No. 52,448 filed July 6,.1970, entitled ANOIL MOP AND METHOD OF USING SAME.

With the foregoing and other objects in view, the invention will be morefully described hereinafter,and will be more particularly pointed outinthe claims appended hereto.

In the drawings, wherein like symbols refer to like or correspondingparts throughout the several views.

FIG. 1 is a side elevational schematic view of an oil well rigconstructed in accordance with the present invention having'parts brokenaway and parts shown in section.

FIG. 2 is an end elevational view of the oil well and rig of FIG. 1.

FIG. 3 is a transverse section taken on the line 3-3 in FIG. 1.

Referring now to FIG. '1 of the drawings, the mop'10 is threaded througha system of sheaves and pulleys to a subterranean oil, or oil and waterpool 11 where it will sorb oil. The mop is spliced end to end making itendless and rotativepower is supplied tothe pulley system to cause themop to' travel continuously as an endless belt, up an eecentrically.mounted tubing stringer 12 through the pulleys and sheaves .and backdown a casing 13 to a return idler sheave 14 mounted in a cartridge 15submerged in or belowthesubterranean oil pool 11. As the mop 10 passesaround the idler sheave 14 it is pulled through the oil, or oil andwater, where it sorbs oil and tends to reject water. The portion of theendless mop 10 which has sorbed oil is pulled up through the tubingstringer 12 to the surface of the earth where it is guided through asystem of squeegee rolls, constructed to pull and cleanse the mop bywringing out, washing out, blowing out, slinging out by centrifugalforce, heated, or a combination of any of these methods into acollection pan 16 as produced crude oil. The unladened portion of themop 10 is trained by a system of guide idler sheaves 17, 18 back to thecasing 13 where it is pulled back down to the subterranean oil pool 11to sorb additional oil and thence in continuous operation.

Referring to the drawings and to follow the path of the continuouslyoperating mop l0 and to understand the function of each component, startwhere the continuously operating unladened mop 10 enters the casing 13.The approximately 4-inch to 24-inch diameter casing 13 has beenimplanted in the earth to a subterranean oil or oil and water pool 11.The casing 13 provides an annular space for eccentrically mounting thetubing stringer 12 and an enclosure for the oil ladened mop l0,-spacefor the unladened mop 10 to travel back to the surface of the earth, andas a guide and a lateral support for the return idler cartridge 15.After reaching the surface of the oil poolthe mop 10 is pulled through areturn guide idler 14, mounted in the cartridge 15, to sorb oil forpassage to the surface of the earth. The cartridge 15 is a multiplefunctioning device; i.e., it provides a support for the return guideidler 14, it provides .a means of adjusting the penetration into and/orbelow the oil pool 11 from'the surface of the earth by raising orlowering the tubing stringer 12, it is equipped with ports 19 that maybe used to adjust the degree of sorption saturation of the mop 10 byeither withdrawing the cartridge 15 into the casing making a portedvalve of the ports between the cartridge 15 and casing 13 or submergingthe cartridge .15 into the subterranean water 11 which again will make aported valve out of the cartridge ports 19 byusing the oil-waterinterface as the body segment of the ported valve with respect to theoil, the casing also functions as a circular guide and horizontalsupport for the cartridge 15.

After'the mop 10 has sorbed crude, oil in the cartridge 15 the oilladened mop 10 travels up the tubing stringer 12 to the earths surface.The tubing stringer 12 is rigidly attached to the cartridge 15 and byraising or lowering the tubing 12 the elevation of the cartridge 15 maybe set. The tubing 12 serves as an enclosure for the oil ladened mop 10to prevent the interchange of oil from the ladened mop to the cleansedmop. If the viscosity of the oil is relativelylow, flexible solidcircular disc spacers 20 a few thousandths of an inch smaller indiameter than the tubing are attached to the wire rope, or the rope, tofunction as pistons in the cylindrical tubing stringer 12. If the discs20 are installed, the sorbic properties of the mop would function toselectively convey the crude oil from the subterranean oil pool 11 tothe vertical tubing 12 and thence most of the force necessary to conveythe oil to the surface of the earth would 'be supplied by the discs 20.The sorbic material 21, such as fiberlated polypropylene may besandwiched between the discs in lieu of interweaving it intothe wire orrope when the discs 20 are used.

As the mop 10 brings the, oil to the surface it leaves the tubing 12 andis guided by guide idlers 22, 23 to a set of squeegee rollers 24, 25 forwringing. The first set of squeegee rollers 24, 25 may be eithervariable purchase or constant purchase pulleys. One or more sets of thevariable purchase squeegee rolls 24, 25 may be used to more evenlydivide the power delivered to the oil ladened mop 10 for pulling it tothe earths surface, reducing wear, and enhancing the mops life.

Referring to the drawing, roll 24 and roll 25 are mounted to receivepower from their respective shafts through an overunning clutch. Theshaft of roll 24 is driven in a reverse direction by a chain 26 andsprocket 27 from the shaft 28 of roll 25 and roll 25s shaft is chain andsprocket driven from a drive shaft 29 common to all other squeegeeroller drives Roll 24 is bearing mounted on a pivoting frame that isbearing mounted to roll 25 s shaft and is free to rotate around roll 25circumference to circumference.

When the frame is horizontal, the one point of contact between the mop land the squeegee rollers 24, 25 provides a minimum, near zero, of powerto the traveling mop 10. An outside force is applied to the framerotating roll 24 in the upward direction so that roll 25 will alwayspull the mop directly out of the tubing 12. As roll 24 is rotated upwardthe mop is forced to lay, as it travels upward, first on roll 25 andthen on roll 24. As roll 24 is rotated around roll 25 in a clockwisedirection the system achieves its maximum purchase of the mop 10. Byvarying the degree of rotation of roll 24 around roll 25 first in aclockwise direction to increase the purchase and then counterclockwiseto decrease its purchase, the degree of purchase may be varied and theamount of power added to the mop 10 therefore controlled. The variablepurchase squeegee rolls 24, 25 also serve to wring the mop 10.

- The mop 10 leaves the variable purchase squeegee rollers 24, 25 andenters constant purchase squeegee rolls 30, 31, 32. The constantpurchase squeegee rolls consist of the rolls 30, 31, 32. Roll 31 isspring or weight loaded to bear against rolls 30 and 32. The drive tothese rolls drive them in unison with each other and in unison with allvariable purchase rolls. The constant purchase rolls 30, 31, 32 add analmost constant amount of power to the mop l0 and provide a purchase onthe mop 10 to overcome any upsets to the system.

Leaving the constant purchase system the mop 10 enters the guidedtake-up idler sheave 33 which takes up slack in the mop 10 due to thestretch in the cable or rope caused by the burden of oil on the upwardleg of the journey. The idler sheave 33 is weight or spring loaded toposition itself according to the stretch in the cable or rope whichserves as an indicator to position the degree of purchase of thevariable purchase rolls 24, 25 and to trip a clutch mechanism 34 on thedrive on overload. This indicating signal could just as easily beobtained from the torque on the constant purchase pulley shafts or thecurrent drawn by the motor, if the drive is electric.

The oil squeezed from the mop 10 by rolls 24, 25 and rolls 30, 31 and 32is recovered by pan l6, and oil which otherwise would have been tooexpensive to recover has been saved.

What I claim is:

l. The method of removing oil from a subterranean oil pool comprising a.threading an endless mop of petrophilic hydrophobic fibers through asystem of sheaves and pulleys to an oil and water pool,

b. driving the mop continuously through the pulleys and sheaves to raisethe oil laden mop to the surface, and

c. removing the oil from the oil laden mop and collecting same whilereturning the cleansed mop to the subterranean pool to sorb more oil.

2. The method of claim 1 further comprising the step of sinking a casingthrough the earth to communicate with the oil pool.

3. The method of claim 1 wherein the endless mop of petrophilichydrophobic fibers comprises a wire rope having polypropylene strips ofthe order of 3 mils thick by :6 inches wide and 4 to 16 inches longdirectly attached to said rope.

4. The method of claim 1 wherein the means for driving the mopcontinuously is a prime mover connected by clutch to drive squeegeerolls in positive driving and squeezing engagement with the mop abovethe ground for squeezing the oil from the oil laden mop prior toreturning the mop to the oil pool.

5. An oil rig for removing oil from a subterranean oil pool comprisinga. a casing communicating between ground level and an oil pool,

b. an endless mop of petrophilic hydrophobic fibers secured to a wirerope,

c. a system of sheaves and pulleys associated with said casing and-mopto cause the mop to travel continuously from the oil pool where it sorbsoil up the casing and back down to the oil pool,

d. squeegee means at opposite sides of the mop above ground for drivingthe mop to raise the oil laden mop to the surface and squeeze the oiltherefrom prior to returning it to the oil pool, and

e. oil collecting means positioned above ground and beneath the squeegeemeans to collect oil brought to the ground leve and squeezed from themop.

6. An oil rig as claimed in claim 5 wherein the casing has therein aneccentrically mounted tubing through which the oil laden mop is pulledto the surface prior to being subjected to the squeegee action of thedriving rolls.

7. An oil rig as claimed in claim 5 wherein said squeegee means are twosets of opposed rolls between which the mop is passed, the first set ofrolls being of variable purchase while the second set of rolls are ofconstant purchase.

8. An oil rig as claimed in claim 7 further comprising a guided take upidler sheave between the constant purchase squeegee rolls and the casingto take up slack in the mop due to the stretch in the wire rope causedby the burden of oil on the upward leg of the journey, and compensatingmeans loaded to position itself according to the stretch in the wirerope which controls the degree of purchase of the variable purchasesqueegee rolls and to disengage the drive to said rolls on overload.

9. The method of claim 1 wherein the removal of the oil from the oilladen mop is accomplished by a wringing action.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,774,685 Dated November 27, 1973 Inventor(s) HERBERT RHODES It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

The assi'gnee should read: OIL MOP INC.

Signed and sealed this 2nd day of April 19714..

(SEAL) Attest:

EDWARD M.FLE TCHER,JR. Y I c. MARSHALL DANN Attesting OfficerCommissioner of Patents

1. The method of removing oil from a subterranean oil pool comprising a. threading an endless mop of petrophilic hydrophobic fibers through a system of sheaves and pulleys to an oil and water pool, b. driving the mop continuously through the pulleys and sheaves to raise the oil laden mop to the surface, and c. removing the oil from the oil laden mop and collecting same while returning the cleansed mop to the subterranean pool to sorb more oil.
 2. The method of claim 1 further comprising the step of sinking a casing through the earth to communicate with the oil pool.
 3. The method of claim 1 wherein the endless mop of petrophilic hydrophobic fibers comprises a wire rope having polypropylene strips of the order of 3 mils thick by 1/8 inches wide and 4 to 16 inches long directly attached to said rope.
 4. The method of claim 1 wherein the means for driving the mop continuously is a prime mover connected by clutch to drive squeegee rolls in positive driving and squeezing engagement with the mop above the ground for squeezing the oil from the oil laden mop prior to returning the mop to the oil pool.
 5. An oil rig for removing oil from a subterranean oil pool comprising a. a casing communicating between ground level and an oil pool, b. an endless mop of petrophilic hydrophobic fibers secured to a wire rope, c. a system of sheaves and pulleys associated with said casing and mop to cause the mop to travel continuously from the oil pool where it sorbs oil up the casing and back down to the oil pool, d. squeegee means at opposite sides of the mop above ground for driving the mop to raise the oil laden mop to the surface and squeeze the oil therefrom prior to returning it to the oil pool, and e. oil collecting means positioned above ground and beneath the squeegee means to collect oil brought to the ground leve and squeezed from the mop.
 6. An oil rig as claimed in claim 5 wherein the casing has therein an eccentrically mounted tubing through which the oil laden mop is pulled to the surface prior to being subjected to the squeegee action of the driving rolls.
 7. An oil rig as claimed in claim 5 wherein said squeegee means are two sets of opposed rolls between which the mop is passed, the first set of rolls being of variable purchase while the second set of rolls are of constant purchase.
 8. An oil rig as claimed in claim 7 further comprising a guided take up idler sheave between the constant purchase squeegee rolls and the casing to take up slack in the mop due to the stretch in the wire rope caused by the burden of oil on the upward leg of the journey, and compensating means loaded to position itself according to the stretch in the wire rope which controls the degree of purchase of the variable purchase squeegee rolls and to disengage the drive to said rolls on overload.
 9. The method of claim 1 wherein the removal of the oil from the oil laden mop is accomplished by a wringing action. 